Complete Achilles Tendon rupture

Naming of the Achilles tendon

The Achilles tendon is named after the warrior and hero of Homer’s Iliad, Achilles.  Achilles, according to myth, was protected from injury by being dipped in a magical pond by his mother.  She held him by the heel, which was not immersed, and he later died by an arrow in his heel.  Although, injuries to this area must have been known for more than 2,000 years, Ambroise Pare first reported it in the medical literature 400 years ago (Pribut, 2003).

Anatomy and Function

            The Achilles tendon is the largest tendon in the body.  It is the thick band of tissue in the back of the lower leg that connects the gastrocnemius and soleus muscles to the calcaneus (heel bone). The gastrocnemius starts behind the knee and overlaps the soleus, starting below the knee, before joining together to form the Achilles tendon.  Some fibers continue distally to where portions of the plantar fascia insert into the plantar aspect of the calcaneus.  The tendon itself is covered by a thin sheath of paratenon, rather than a true synovial sheath.  This allows easy gliding of the tendon.  When the gastrocnemius muscle in the calf contracts, the Achilles tendon is tightened, pulling the heel.  This allows you to point your foot and stand on tiptoes.  It is vital to such activities as walking, running, and jumping.

Risk Factors

            There are a number of factors that predispose the Achilles tendon to injury or rupture.  Ruptures of the Achilles tendon can be seen on any athlete but are most commonly seen in “weekend warriors,” usually 30-50 year-old men.  Males have an increased injury ratio of 5:1 over females (Altman & Blake, 2003).  Individuals in this age group still have great muscular strength, but are beginning to lose flexibility and are not able to withstand the forces required in sports.  With professional athletes, most Achilles injuries occur in the quick acceleration/jumping-type sports like basketball or racquetball.  Thus, injuries can occur from simply overstretching your Achilles tendon while doing a simple activity, such as gardening.  Not only do the middle-aged lack in flexibility, they also lack an adequate supply of blood to the tendon.  Other risk factors include certain illnesses, peritenonitis (a.k.a. Achilles tendonitis), tendinosis, peritenonitis with tendinosis, previous Achilles tendon injury or rupture, and oral or injected steroids.  Paretenonitis is an inflammation and swelling of the paratenon, a sheath surrounding the Achilles tendon, caused by repetitive strain or over-use.  This injury is common in triatheletes.  Tendinosis refers to degeneration within the tendon due to a previous rupture or tear that may or may not be associated with swelling and signs of inflammation.  Patients with tendinosis may complain of a sensation of fullness or a cord in the back of the leg.  Paratendinitis involves not only inflammation of the paratenon , but also a degenerative change within the substance of the tendon.  If not treated and rehabilitated correctly, tendinosis and paratenonitis can lead to a complete rupture (Abelson, 2003).  The use of steroid injections for cases of paratenonitis with or without tendinosis needs to be carefully considered because steroid injections can cause even greater deterioration of the tendon (Horwitz, 1999).  These factors all increase your risk of a rupture.

Mechanism of Injury

            The Achilles tendon can withstand a force of 1000 pounds without tearing, making it the strongest in the body (Horwitz, 1999).  Despite its tremendous strength, the Achilles tendon is the second most frequently ruptured tendon in the body.  Most ruptures occur about two to three inches proximal to where the tendon inserts the calcaneus (heel bone).  This area is the narrowest part of the tendon and has the poorest blood supply, making it more prone to injury and rupture.  Indirect trauma is the most common mechanism and likely results from a combination of tendinosis degeneration and mechanical loading.  The following overloading forces can result in tendon failure: 1.) forceful plantar flexion of the foot while the knee is extended, such as starting a sprint.  This is also the most common mechanism of injury. 2.) Unexpected rapid dorsiflexion of the foot, as in stepping into a hole or stepping on a curb unexpectedly, and  3.) violent dorsiflexion when jumping from a great height and landing on a plantar flexed foot (Altman & Blake, 2003).

Signs and Symptoms

            Athletes that have ruptured the Achilles tendon often report feeling a “shot” or “kick” in the back of the calf and then having severe sharp pain.  This will often be followed by a loud “pop” or “snap” sound and swelling. There can also be muscle spasms in the lower half of the leg.  A complete rupture is more common than a partial rupture. With a complete rupture, the athlete will not be able to rise on the toes or push off on the injured leg to walk properly.  The patient may limp.  Normally, there is a gap between the torn ends of the tendon, usually two inches above the calcaneus.  With a partial rupture, he may still be able to move his foot, and he may experience only minor pain and swelling.

Diagnosis

It is estimated that 20%-25% of initial injuries are missed (Altman & Blake, 2003).  Diagnosis is largely made based upon the history and physical examination.  X-rays usually are not taken unless it is suspected that the calcaneus, where the Achilles tendon attaches, is injured.  In some cases, the tendon will not rupture, but instead, it will pull a piece of the calcaneal bone off of the calcaneus.  The rupture can be confirmed by a positive Thompson test.  This test in performed by squeezing the calf while the patient lies on their stomach with the affected leg bent at the knee.  When the calf is squeezed, the foot should plantar flex (bend forward).  If the foot does not plantar flex or move, then the Achilles tendon is completely torn.  Both sides should be compared.  Another test is Copeland’s pressure test.  Copeland’s test is performed using a blood pressure cuff attached around the calf.  With the foot in plantar flexion, the cuff is inflated to a pressure of 100 mm Hg.  If the tendon is intact, dorsiflexion of the foot will cause the pressure to rise to 140 mm Hg.  The pressure remains unaltered if the tendon is ruptured (Campbell, 1993).  An MRI will accurately reveal the extent of the rupture.  Diagnostic ultrasound is also used to assist in the diagnosis of a ruptured Achilles tendon. 

Prevention

            Good conditioning and proper stretching are essential in the prevention of Achilles tendon ruptures.  Warming up before exercising, as well as, cooling down after exercising will help to avoid an Achilles tendon injury.  An athlete should also perform calf muscle strengthening exercises before taking part in physical activity.  For example, practicing toe raises by raising up on the toes and holding for 30-60 seconds and slowly lowering the heel.  It will also help to alternate high and low impact exercises so the athlete does overwork the Achilles tendon.  Stretching the Achilles tendon can also help prevent an injury.  Never bounce during and stretch and only until you feel a pull, not pain.  Shoes with a proper fit and heel counter will also help prevent Achilles injuries.  Anyone who exercises, whether professionally or not should be aware of proper conditioning to avoid injury.

Surgical and Nonsurgical Treatment

Treatment options for an Achilles tendon rupture are surgical or nonsurgical.  There are advantages and disadvantages to each technique.  Both surgical and nonsurgical treatments will require casting or special braces for about six weeks.  The cast can be changed at 2 to 4 week intervals to slowly stretch the tendon back to its normal length (Nannini, 2001).  By casting, this can cause early movement to improve overall strength and flexibility.  With surgery, the tendon is either reattached to the calcaneal bone if it has been pulled off or the two ends are sewn together if the tendon has been torn in two.  Choosing to do the surgery causes you to have a lower incidence of re-rupture than nonsurgical treatment.  It allows you to pre-injury activities sooner and at a higher level of functioning with less shrinkage of muscle.  But, there are risks that are associated with surgery.  You can get anesthesia, infection, skin breakdown, scarring, bleeding, accidental nerve injury, and blood clots in the leg.  Also it is a higher cost.

Nonsurgical Treatment   

Nonsurgical treatment is often used for nonatheletes, or those with a general low level of physical activity who would not benefit from surgery.  The elderly and those with complicating medical conditions also get nonsurgical treatment.  Nonsugical treatment involves extended casting, special braces, orthotics, and physical therapy.  Some studies show that the outcome is similar to surgery in regard to strength and function.  This choice of treatment avoids normal complications and expenses of surgery.  It has a higher incidence of re-rupture than surgical repair. 

Rehabilitation

Rehabilitation is required to strengthen the tendon.  There are many exercises that can be done to help strengthen the tendon.  Heel lifts are used to reduce strain on the Achilles tendon, and cross-fiber friction to improve circulation.  In order to return to a function completely you are required attention to range of motion, functional strength, and orthotic support (Christensen, 2003).  Stretching of the tight and shortened gastrocnemius/soleus muscle complex is a necessary part of Achilles tendon rehabilitation.  Gentle stretching should be started early by putting a linear stress on the tendons and stimulating connective tissue.  The standard exercise for this is the “runner’s stretch.” (Christensen, 2003) Isotonic strengthening exercises focus on the eccentric component that improves the healing of tendons and accelerates the return to sport participation.  A shoe insert made of visoelastic material will help decrease the amount of stress on the feet, legs, and back during running.  Most Achilles tendon problems after surgery develop from poor foot and ankle biomechanics.  To prevent recurrent injuries you need to control pronation.  Custom made, flexible orthodics are now available that can support the hind foot, midfoot, and forefoot.  Orthotics has been found very useful in the long term improvement.

Outlook

The outlook on people for Achilles tendon rupture is good.  The majority of people return to normal activity levels with either surgical or nonsurgical treatment.  Most studies indicate a better outcome with surgery.  Athletes can expect a faster return to activity with a lower incidence that the injury will happen again.  As the rupture site heals, a small lump remains from scarring .  Weight bearing commonly begins at about 6 weeks with a heel support.  Many return to running and athletics about 4 to 6 months.  With motivation and rigorous physical therapy, athletes may return to athletics as early as 3 months after injury.          

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

References

Campbell. Spontaneous Rupture of Achilles Tendon - pathology and management.     BJHM; 1993; 50; 6:321-5

Christensen, Kim P.  (2003, November 25).  Rehab of the Achilles Tendon.      http://www.ccptr.org/KDC/rehab_of the achilles__tendon.htm

Nannini, Christopher A., MD. (2001, February 26).  Achilles Tendon Rupture.           (Rev. 2001, February 26).  http://www.emedicine.com/aaem/topics4.htm.  (25 Nov. 2003).

Pribut, Stephen M., MD.  (2003).  Dr. Pribut on Injuries.   http://www.drpribut.com/sports/spinjur.html.  (25 Nov. 2003).

Altman, Alan L., MD and Blake, William J., DPM.  Achilles Tendon Injuries. (2003,       November 25).  http://www.bonesrus.com/Achilles.html

Horwitz, Steven M.  Achilles Tendon.  (1999).  http://youcanbefit.com/ach.html.  (25 Nov. 2003).

Abelson, Brian DC, ART., MD.  (2003).  Injuries to the Achilles Tendon.  http://activerelease.net/drquotes/art_spotlight15.cfm.  (25 Nov. 2003).